Lightning protection system and method for wind turbine blades

ABSTRACT

A method of installing a lightning protection system can include forming a blade wall of a wind turbine to at least partly include a socket. A part of the socket can be removed, after forming the blade wall, to provide an opening through the blade wall. A receptor plug and a receptor element can be secured to the socket at the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 15/153,978, filed on May 13, 2016, the entirety ofwhich is incorporated herein by reference.

BACKGROUND

Wind turbines and other structures can be subject to lightning strikes,which can potentially damage the structures themselves, damageelectronic or other components supported by the structures, or result inother detrimental effects. Accordingly, it can be useful to provide windturbines and other structures with lightning protection systems in orderto appropriately route electrical current from lightning strikes to theground.

Conventional lightning protection systems for wind turbines generallyadopt one or more of three approaches for protecting wind turbine blades(here, generally, “blades”) from lightning strikes. A first conventionalapproach uses tip receptors, which are generally configured ascylindrical conductors that protrude through the distal fins ofrespective blades, or as conductive end caps that generally match therelevant blade profiles. Generally, a tip receptor is connected to adown conductor, or earthing electrode, which extend from a connection ofthe down conductor with the tip receptor, through an internal cavity ofthe turbine blade, to the blade root. Some conventional designs can alsouse an anchoring block, also referred to as a receptor block, that canbe located within the blade cavity some distance away from the blade tipand can provide an electro-mechanical bonding junction for the tipreceptor and the down conductor.

A second conventional approach uses conductive surface receptor disks,each with a respective exposed face and receptor body. A receptor bodyis generally recessed into the relevant blade wall and can sometimesextend into the relevant blade cavity. Generally, the exposed face of areceptor disk is circular, while the shape of the receptor body canvary. In some installations, receptor disks are disposed near thetrailing edge of a blade. In some installations, several receptor diskscan be arranged at various points along the length of the blade, withthe number of receptor disks dependent upon the length of the blade. Insome installations, sets of receptor disks can be disposed near the tipof a blade in lieu of a tip receptor (e.g., as described above).

A third conventional approach uses blade coverings, which are generallyconfigured as conductive layers that extend over a relatively large areaof the surface of a blade. The layers of the blade coverings can beformed as continuous solids, meshes, or cured resins. Generally, theblade coverings are applied in sheets, strips or patches, and can beplaced on the exterior surface of a blade or just below a surfacecoating of the blade.

SUMMARY

Some embodiments of the invention provide a lightning protection systemfor a wind turbine blade with a blade wall and a blade cavity. A socketcan be configured to extend at least partly through the blade wall, andcan include a socket body and a plurality of first teeth. A receptorplug can be configured to be secured to the socket with the receptorplug disposed at least partly within the blade cavity, and can include aplug body, a plug conductor at least partly enclosed by the plug body,and a plurality of second teeth. The plurality of first teeth can engagethe plurality of second teeth, when the receptor plug is secured to thesocket, to resist rotation of the receptor plug relative to the socket.

Some embodiments of the invention also provide a lightning protectionsystem for a wind turbine blade with a blade wall and a blade cavity. Asocket can be configured to extend at least partly through the bladewall, and can include a non-conductive socket body with an opening and afirst retention shoulder. A receptor plug can include a non-conductiveplug body, a plug conductor at least partly enclosed by thenon-conductive plug body, and a second retention shoulder. A receptorelement can be configured to connect to the receptor plug to transmitcurrent from lightning strikes to the plug conductor. The secondretention shoulder can engage the first retention shoulder to secure thereceptor plug to the socket, with the non-conductive plug body disposedat least partly within the blade cavity. The receptor element canconnect to the receptor plug, when the receptor plug is secured to thesocket, via the opening in the non-conductive socket body.

Some embodiments of the invention provide a lightning protection systemfor a wind turbine blade with a tip receptor that includes a conductivebody with a receptor profile. A tip receptor mount can include areceptor mount body, at least two bonding wings, a conductor, and aconductive connector. Each of the bonding wings can extend away from thereceptor mount body, and can include a respective non-conductivelattice. The conductor can be at least partly included in the receptormount body. The conductive connector can extend at least partly outsideof the receptor mount body. The tip receptor can be secured to the tipreceptor mount with the conductive connector. The bonding wings can besecured to the wind turbine blade with a bonding material that at leastpartly fills the non-conductive lattices.

Some embodiments of the invention provide a method of installing alightning protection system in a blade wall formed on a blade mold,where the lightning protection system includes a receptor plug, areceptor element, and a socket with a bottom wall. The bottom wall ofthe socket can be placed on the mold. The blade wall can be formed onthe mold so that the blade wall is formed around, and at least partlyincludes, the socket. At least part of the bottom wall of the socket canbe removed to provide an opening through the blade wall via the socket.The receptor plug can be secured to the socket, with the receptor plugon an interior side of the blade wall. After the at least part of thebottom wall is removed, the receptor element can be secured to thereceptor plug via the opening.

Some embodiments of the invention provide a method of installing alightning protection system in a wind turbine blade with a first bladewall formed on a first blade mold, a second blade wall formed on asecond blade mold, and a blade cavity formed when the first blade wallis secured to the second blade wall, where the lightning protectionsystem includes a first socket with a first bottom wall, a second socketwith a second bottom wall, a first receptor plug, a second receptorplug, a first receptor element, and a second receptor element. The firstbottom wall of the first socket can be placed on the first blade mold.The first blade wall can be formed on the first blade mold so that thefirst blade wall is formed around and at least partly includes the firstsocket. At least part of the first bottom wall of the first socket canbe removed to provide a first opening through the first blade wall viathe first socket. The first receptor plug can be secured to the firstsocket with the first receptor plug on an interior side of the firstblade wall. The second receptor plug can be temporarily secured to theinterior side of the first blade wall.

The second bottom wall of the second socket can be placed on the secondblade mold. The second blade wall can be formed on the second blade moldso that the second blade wall is formed around and at least partlyincludes the second socket. The first blade wall can be joined to thesecond blade wall to form the blade cavity. At least part of the secondbottom wall of the second socket can be removed to provide a secondopening through the second blade wall via the second socket.

After removing the at least part of the first bottom wall, the firstreceptor element can be secured to the first receptor plug via the firstopening. After removing the at least part of the second bottom wall, thesecond receptor plug can be accessed via the second opening to removethe second receptor plug from the first blade wall and secure the secondreceptor plug to the second socket. The second receptor element can besecured to the second receptor plug via the second opening.

Some embodiments of the invention provide a method of installing alightning protection system in a blade wall formed on a mold, where thelightning protection system includes a receptor plug, a receptorelement, and a socket with a bottom wall. The bottom wall of the socketcan be placed on the mold. The blade wall can be formed on the mold sothat the blade wall is formed around and at least partly includes thesocket. At least part of the bottom wall of the socket can be removed toprovide an opening through the blade wall via the socket. The receptorplug can be secured to the socket with the receptor plug on an interiorside of the blade wall. After removing at least part of the bottom wall,the receptor element can be secured to the receptor plug via theopening.

Some embodiments of the invention provide a method of installing alightning protection system in a wind turbine blade with a first bladewall formed on a first blade mold, a second blade wall formed on asecond blade mold, and a blade cavity formed when the first blade wallis secured to the second blade wall. A first bottom wall of a firstsocket can be placed on the first blade mold. The first blade wall canbe formed on the first blade mold so that the first blade wall is formedaround and at least partly includes the first socket. After forming thefirst blade wall, a first opening can be provided through the firstblade wall via the first bottom wall of the first socket. A firstreceptor plug can be secured to the first socket with the first receptorplug at least partly disposed on an interior side of the first bladewall.

A second bottom wall of a second socket can be placed on the secondblade mold. The second blade wall can be formed on the second blade moldso that the second blade wall is formed around and at least partlyincludes the second socket. The first blade wall can be joined to thesecond blade wall to form the blade cavity with the second receptor plugdisposed within the blade cavity. After forming the second blade wall, asecond opening can be provided though the second blade wall via thesecond bottom wall of the second socket. The second receptor plug can beaccessed via the second opening to secure the second receptor plug tothe second socket.

Some embodiments of the invention provide a method of installing alightning protection system in a wind turbine blade. A first blade wallcan be formed around a first socket so that an integrally formed firstsocket wall of the first socket separates a first internal opening ofthe first socket from an exterior side of the first blade wall. At leastpart of the integrally formed first socket wall can be removed toprovide a first opening through the first blade wall into the firstinternal opening of the first socket. A first receptor plug can besecured to the first socket with the first receptor plug at least partlydisposed to an interior side of the first blade wall. A first receptorelement can be secured to the lightning protection system to provide aconductive path from the exterior side of the first blade wall to thefirst receptor plug via the first internal opening of the first socket.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles ofembodiments of the invention:

FIG. 1 is a perspective view of part of a wind turbine blade and alightning protection system for the blade, according to some embodimentsof the invention, with a top portion of the blade removed to showaspects of the lightning protection system;

FIG. 2 is a perspective view of a branch for use with the lightningprotection system of FIG. 1, including two side receptor plugs and a tipreceptor mount

FIGS. 3A through 3D are bottom plan, side elevation, top plan, and frontelevation views, respectively, of a side receptor plug for use with thelightning protection system of FIG. 1;

FIGS. 4A and 4B are bottom, front, left perspective and top, front,right perspective views, respectively, of the side receptor plug ofFIGS. 3A through 3D;

FIG. 5A is a bottom, front, left sectional perspective view of the sidereceptor plug of FIGS. 3A through 3D;

FIG. 5B is a side sectional view of another side receptor plug for usewith the lightning protection system of FIG. 1;

FIGS. 6A through 6C are bottom plan, side elevation, and top plan views,respectively, of a socket for use with the lightning protection systemof FIG. 1;

FIG. 7 is a top, left, front sectional perspective view of the socket ofFIGS. 6A through 6C;

FIG. 8 is a top, left, front perspective view of the socket of FIGS. 6Athrough 6C, with a tear-away tab of the socket having been removed;

FIGS. 9 and 10 are top, left, front perspective views of additionalsockets for use with the lightning protection system of FIG. 1;

FIGS. 11A through 11C are top, bottom, and cross-sectional perspectiveviews, respectively, of a side receptor disk for use with the lightningprotection system of FIG. 1;

FIGS. 12A through 12C are a side elevation, top plan, and frontelevation views, respectively, of a tip receptor mount for use with thelightning protection system of FIG. 1;

FIG. 13 is a top, left, front perspective view of the tip receptor mountof FIGS. 12A through 12C;

FIG. 14 is a top, left, front, partial sectional perspective view of thetip receptor mount of FIGS. 12A through 12C;

FIG. 15A is a bottom, rear, left perspective view of a tip receptor fora wind turbine blade;

FIG. 15B is a bottom, rear, left sectional perspective view of the tipreceptor of FIG. 15A, taken along plane A-A of FIG. 15A

FIG. 16A is a top, left, front perspective view of the tip receptormount of FIGS. 12A through 14 secured to the tip receptor of FIGS. 15Aand 15B;

FIG. 16B is a top, left, front, partial sectional perspective view ofthe tip receptor mount and tip receptor of FIG. 16A;

FIG. 17 is a top, left, rear perspective view of another tip receptormount for use with the lightning protection system of FIG. 1; and

FIGS. 18A through 18K illustrate an installation method for parts of thelightning protection system of FIG. 1.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items.

Unless otherwise specified or limited, the phrases “at least one of A,B, and C,” “one or more of A, B, and C,” and the like, are meant toindicate A, or B, or C, or any combination of A, B, and/or C, includingcombinations with multiple instances of A, B, and/or C. Likewise, unlessotherwise specified or limited, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings. Further, unless otherwise specified or limited, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings. For example, in some cases, “connected” elements can beelectrically connected, including through direct contact or through anintermediary object or medium.

The following discussion is presented to enable a person skilled in theart to make and use embodiments of the invention. Various modificationsto the illustrated embodiments will be readily apparent to those skilledin the art, and the generic principles herein can be applied to otherembodiments and applications without departing from embodiments of theinvention. Thus, embodiments of the invention are not intended to belimited to embodiments shown, but are to be accorded the widest scopeconsistent with the principles and features disclosed herein. Thefollowing detailed description is to be read with reference to thefigures, in which like elements in different figures have like referencenumerals. The figures, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope ofembodiments of the invention. Skilled artisans will recognize theexamples provided herein have many useful alternatives and fall withinthe scope of embodiments of the invention.

Some figures may include multiple instances of similar structures orstructural relationships. For convenience of presentation, in selectfigures, only some of these similar structures or relationships may bespecifically labeled with a reference number. One of skill in the artwill recognize that the features not labeled with reference numbers caninclude similar aspects and perform similar functions to similarfeatures that are labeled with reference numbers.

In discussion of certain figures, directional references such as up,down, top, bottom, left, right, and so on may be used. Unless otherwisespecified, these references are provided for convenience only, and withrespect only to the particular figure(s) and embodiment(s) discussed.

Embodiments of the invention can improve on conventional lightningprotection (“LP”) systems in different ways. In the context of windturbine blades (here, generally, “blades”), embodiments of the inventioncan reduce the difficulty of installation as compared to conventionallightning protection systems, as well as the need for significantpost-processing work after the blades have been closed. For example,under one conventional installation process for conventional LP systems,a receptor block (e.g., solid piece of metal) is built into a bladecavity. Once the blade has been closed, the receptor block must belocated and then drilled and tapped so that a receptor disk (or otherreceptor element) can be secured to the metal piece. This process can berelatively difficult and time consuming. In another conventionalinstallation process for conventional LP systems, a hole must be cutinto a blade wall once the blade has been closed. Once the hole has beencut, a conductive connection is made through the cut hole, and the holethen patched to re-finish the blade. Again, this process can berelatively difficult and time consuming.

Some embodiments of the invention can provide a LP system that can notonly generally reduce the difficulty of the installation process, butalso significantly reduce the need for post-processing work that may berequired under conventional LP systems. For example, embodiments of theinvention can include sockets that can be molded into blade walls as theblade walls are being formed. Once the blades have been formed, a partof the sockets can be removed in order to provide consistent, engineeredmounting holes through the blade walls for securing and connectingreceptor disk. Further, the sockets can provide for relatively easyattachment of associated plugs, in order to transmit electrical currentfrom the receptor disks to the relevant down conductor. As such, throughuse of the sockets, receptor disks can be installed to blades, and canbe electrically connected to down connectors, without the need to cutand repair (or otherwise post-process) the blades.

In some embodiments of the invention, a LP system can include a tipreceptor mount that can be easily adapted to attach to, and conductelectrical current from, a variety of different tip receptors. This canallow for tip receptors to be customized to particular blade profiles,without necessarily requiring significant reconfiguration of theassociated tip receptor mounts. Further, the tip receptor mount caninclude non-conductive bonding features, such as bonding wings with anon-conductive lattice, to receive bonding material (e.g., resin) inorder to help secure the tip receptor mount to a blade.

Some embodiments of the invention can provide a method of installationfor LP systems that improves on conventional installation methods. Forexample, multiple sockets (e.g., sockets as described generally above)can be molded into blade walls for both sides of a blade. A number ofplugs with conductors can be installed into sockets on a first side ofthe blade, and additional plugs can be temporarily attached to theinterior of the first side of the blade using adhesives, clips, or othermechanisms. The blade can then be closed by joining the blade wallstogether. Once the blade is closed, the plugs that are attached to theinterior of the first side of the blade with the adhesive, clips orother mechanisms can be visually located through openings in sockets onthe second side of the blade. A relatively simple tool can then beextended through the openings to grab these plugs, remove them from thetemporary attachment at the first side of the blade, and attach them tosockets on the second side of the blade. Each plug that has beenconnected to a socket can then be connected to a receptor disk, whichcan be installed, via the plug, flush with the exterior surface of theblade.

In the discussion below, various examples discuss LP systems accordingto the invention in the context of conventional wind turbine blades. Itwill be understood that this discussion is presented by way of exampleonly, and that the disclosed invention can also be used beneficially inother settings.

FIG. 1 illustrates an LP system 20 according to one embodiment of theinvention. In the embodiment illustrated, the LP system 20 is installedin a blade 22 with a bottom wall 22 a and a top wall (not shown forclarity), which can be separately molded then joined together into theblade 22. Generally, the LP system 20 includes a number of receptors forlightning strikes, which are connected by conductors 24 and by variousjunctions 26 to a down conductor 28. At a distal tip 22 b of the blade22, the LP system 20 includes a metal tip receptor 30. The tip receptor30 is generally shaped to match the local profile of the blade 22 andprovides a conductive receptor surface on the exterior of the blade 22to receive lightning strikes. The tip receptor 30 is secured to a tipreceptor mount 32, which is connected by one of the conductors 24 to thedown conductor 28.

In addition to the tip receptor 30, the LP system 20 also includes aplurality of side receptors, each including a respective socket 34mounted to the relevant wall of the blade 22, a side receptor plug 36secured to the socket 34, and a side receptor disk 38 secured to theside receptor plug 36. (As illustrated in FIG. 1, one of the sidereceptors is shown without a socket 34, to illustrate aspects of theattachment of the relevant side receptor plug 36 to the relevant sidereceptor disk 38.) Generally, the pairs of the side receptor plugs 36and the sockets 34 hold the respective side receptor disk 38 with areceptor surface 38 a of the side receptor disk 38 facing outside of,and flush (i.e., substantially in parallel) with, the relevant wall ofthe blade 22. One of the conductors 24 extends from each of the sidereceptor plugs 36 to connect the side receptors to the down conductor28.

FIG. 1 also illustrates a number of clips 40 secured to the interior ofthe walls of the blade 22. As also discussed below, the clips 40 can beused during installation of the LP system 20 in the blade 22.

It will be understood that the configuration illustrated in FIG. 1 ispresented as an example only, and that other embodiments of thedisclosed LP system can include other numbers or arrangements of sidereceptor plugs, tip receptors, cables, junctions, and other components.In general, FIG. 2 illustrates a “W-splice” configuration that can beused in the LP system 20 or in various other LP systems. In theembodiment illustrated, the W-splice configuration can include two ofthe side receptors (each with a respective one of the side receptorplugs 36) and one of the tip receptor mounts 32 joined to the downconductor 28 with a junction 44. As also illustrated in FIG. 2,connectors such as a lug 46 can be included to help the conductor 28 (orother components) mechanically attach and transfer electrical current toother parts of the system.

In the embodiment illustrated in FIG. 2, one of the side receptor plugs36 is arranged to be secured to one side of a blade and another of theside receptor plugs 36 is arranged to be secured to an opposite side ofthe blade. Accordingly, using the embodiment illustrated in FIG. 2,receptors for lightning strikes can be disposed on both sides of a blade(as well as at the blade tip).

In other embodiments, other configurations are possible. For example,for some blade assemblies, appropriate LP systems can include conductorsof 30-50 meters or more, and can employ significantly more than two sidereceptors. In some embodiments, an individual Y-splice connection foreach side receptor branch can be used (e.g., a Y-splice connection foreach pair of side receptors), as an alternative (or in addition to) theW-splice configuration illustrated in FIG. 2.

FIGS. 3A through 5A illustrate various aspects of one of the sidereceptor plugs 36 of FIG. 1. In the embodiment illustrated, the sidereceptor plug 36 includes an overmolded body 60 with a generallysemi-spherical shell portion 62 and a generally cylindrical neck portion64. The overmolded body 60 is generally formed from a non-conductive(e.g., plastic) material in order to discourage lightning attachment toconductive elements internal to the blade 22, and to generally act as aninsulator for electrical current moving through the LP system 20.

Generally, the shell portion 62 of the overmolded body 60 includes anopen end 66, with a set of retention tabs 68 arranged circumferentiallyaround a shoulder 58 within the open end 66. The retention tabs 68 aregenerally separated from each other by gaps 70, so that the retentiontabs 68 do not extend continuously around the circumference of the openend 66. In the embodiment illustrated, the gaps 70 are generally smallerin circumferential extent than the retention tabs 68. Further, the gaps70 and the retention tabs 68, respectively, have generally similarcircumferential extent to each other. It will be understood, however,that other configurations are possible. For example, a single retentiontab (not shown) of partial or full circumferential extent can be used inplace of (or in addition to) the retention tabs 68.

To help secure the side receptor plug 36 to one of the sockets 34 (asalso discussed below), each of the retention tabs 68 includes a radiallyoutwardly extending retention shoulder 72. Further, a plurality of teeth74 extend from free ends of the respective retention tab 68 away fromthe open end 66. As illustrated, the teeth 74 are configured asgenerally triangular teeth with pointed ends, collectively arranged in asingle, circumferential array. In other embodiments, otherconfigurations are possible. For example, teeth for a receptor plug canalternatively (or additionally) include rounded teeth, square teeth,teeth arranged in a set of circumferential arrays (e.g., each at adifferent radial distance from a reference axis), and so on.

To provide a conductive path through the side receptor plug 36, aconnector, such as a bolt 76, is seated within (e.g., molded into) theshell portion 62 and is in contact with a shell plate 78 also seatedwithin the shell portion 62. The shell plate 78 is partly disposed in anopen internal cavity of the shell portion 62 and is separated from theretention tabs 68 by a shoulder at the open end 66 of the shell portion62. The shell plate 78 is in conductive contact with a conductor such asa cable 80 extending through the neck portion 64 (see FIG. 5A) in orderto electrically connect the side receptor plug 36 to a down conductor(not shown in FIGS. 3A through 5A). As also described below, the bolt 76can be used to secure one of the side receptor disks 38 (not shown inFIGS. 3A through 5A) to the side receptor plug 36. Accordingly,electrical current (e.g., due to a lightning strike at the side receptordisk 38) that enters the side receptor plug 36 via contact between therelevant side receptor disk 38 and the shell plate 78 (or otherwise) canbe transmitted through and out of the side receptor plug 36 via theshell plate 78, the exothermic weld connection 82 (or the compressionlug 88), and the cable 80.

It will be understood that other configurations are possible forsecuring the side receptor disks 38 to the side receptor plugs 36. Forexample, instead of a threaded bolt such as the bolt 76, the sidereceptor disks 38 can include other types of attachment devices, such asacorn/cap nuts, blind press nuts, blind weld nuts, and so on. Similarly,the side receptor disks 38 can include attachment devices other thantapped holes. For example, other side receptor disks can be configuredwith integral threaded bolt features (not shown), that can engage acorresponding tapped hole in a corresponding side receptor plug (notshown).

In the embodiment illustrated in FIG. 5A, the cable 80 is configured asa copper cable that can be secured to the shell plate via an exothermicweld connection 82. This may be useful, for example, because exothermicconnections are generally low resistance, do not loosen or corrode overtime, and exhibit a generally smaller profile than comparable boltedcable lugs and crimped connections. In other embodiments, however, otherconfigurations for conductive connections are possible. For example, asillustrated in FIG. 5B, one or more of the side receptor plugs 36 caninclude an aluminum (or other) cable 84 that can be connected to a bolt86 using a compression lug 88 or other mechanical connector.

FIGS. 6A through 8 illustrate various aspects of one of the sockets 34of FIG. 1, which is generally configured to attach to the side receptorplug 36 of FIGS. 3A through 5A. In the embodiment illustrated in FIGS.6A through 8, the socket 34 generally includes a cylindrical body 100,with an exterior perimeter flange 102. The perimeter flange 102 extendsaround the top end of the socket 34 and includes a lip 104 that anglesgenerally outwardly from a perspective moving downward from the top ofthe socket (i.e., moving right to left in FIG. 6B). In the embodimentillustrated, the flange 102 is also connected to the cylindrical body100 with various flat gussets 108. Like the side receptor plug 36, thesocket 34 is generally formed from a non-conductive (e.g., plastic)material in order to discourage lightning attachment to conductiveelements internal to the blade 22 and to generally act as an insulatorfor electrical current moving through the LP system 20.

The top of the socket 34 includes a central opening 106 divided by acylindrical wall 110 into an internal cylindrical recess 112 and anexternal annular recess 114. A cylindrical flange 116 extends radiallyinwardly from the cylindrical wall 110 into the cylindrical recess 112.A series of retention shoulders 118 extend into annular recess 114, witha radial depth that is generally similar to the radial extension of theretention shoulders 72 (e.g., as illustrated in FIGS. 3A through 5A).Sets of teeth 120 with generally complimentary geometry to the teeth 74(e.g., as illustrated in FIGS. 3A through 5A) are also disposed withinthe annular recess 114 at positions that are separated axially (i.e.,into the page in FIG. 6C) from the retention shoulders 118.

In an initial configuration (e.g., before installation), as illustratedin particular in FIGS. 6A, 6C and 7, the bottom of the socket 34includes a bottom plate 122 that fully closes the bottom of the centralopening 106, but also includes a tear-away tab 124. Generally, atear-away tab can be configured to be relatively easily removed from theremainder of the bottom wall of a socket, at an appropriate time in theinstallation of the LP system 20 (e.g., as also discussed below), inorder to provide an opening in the bottom of the socket 34 (see, e.g.,FIG. 8). In the embodiment illustrated in FIGS. 6A, 6C, and 7, thetear-away tab 124 is configured for manual removal, with a grippingfeature 126 and with a reduced-thickness tear-away profile 128 thatextends within the perimeter of, and at least partly around, thetear-away tab 124. To remove the tear-away tab 124, a user can grasp thegripping feature 126 (e.g., with a tool) and pull generally axiallyrelative to the socket 34. This can result in relatively the material ofthe socket 34 tearing away from the remainder of the bottom plate 122along the tear-away profile 128, thereby allowing the tear-away tab 124to be easily removed from the socket 34. As illustrated in FIG. 8, thiscan result in the central opening 106 extending axially through theentire body of the socket 34, via a generally circular hole 130extending from the cylindrical recess 112 through the bottom plate 122of the socket 34.

As also discussed below, the socket 34 (or other sockets according tothis disclosure) can be molded into a particular blade wall as the bladewall is being formed. Accordingly, sockets of different thicknesses canbe provided in order to accommodate blade walls of differentthicknesses. As illustrated in FIGS. 9 and 10, for example, the sockets34 a and 34 b are generally similar to the socket 34 illustrated inFIGS. 6A through 8, but exhibit a somewhat smaller height and a somewhatlarger height, respectively, than the socket 34.

FIGS. 11A and 11C illustrate aspects of the side receptor disk 38, whichcan be generally configured for attachment to the side receptor plug 36.Generally, the side receptor disk 38 includes the receptor surface 38 aat one axial end of the side receptor disk 38, and a tapped bore 132 atan opposite axial end of the side receptor disk 38. A body 134 of theside receptor disk 38 can be generally formed from conductive material(e.g., aluminum) and includes a shoulder 136, so that the body 134exhibits a generally larger radial extent near the receptor surface 38 athan it does near the tapped bore 132.

In other embodiments, other configurations for a side receptor arepossible. For example, in the side receptor disk 38, the axial end ofthe side receptor disk 38 that is opposite the receptor surface 38 a caninclude a threaded post or other attachment mechanism, in place of thetapped bore 132, to connect the side receptor disk 38 to the sidereceptor plug 36. In some embodiments, a side receptor can be configuredwith non-cylindrical (or other) geometry.

FIGS. 12A through 14 illustrate aspects of the tip receptor mount 32 ofFIG. 1. Generally, the tip receptor mount 32 includes an overmolded body140 with a flared connection portion 142, and a generally cylindricalneck portion 144. The overmolded body 140 can be formed, for example,from non-conductive (e.g., plastic) material in order to discouragelightning attachment to conductive elements internal to the blade 22 andto generally act as an insulator for electrical current moving throughthe LP system 20.

The connection portion 142 of the overmolded body 140 surrounds part ofa conductive connection plate 146 (see, in particular, FIG. 13), withvarious (e.g., three) lugs 148 of the connection plate 146 extendingoutside of the connection portion. The neck portion 144 of theovermolded body 140 surrounds part of a conductor, such as a copper (orother) cable 150. An exothermic weld connection 152 (see FIG. 13), orother type of connection, also surrounded by the body 140, can allowelectrical current entering the tip receptor mount 32 via the lugs 148(e.g., due to a lightning strike on the tip receptor 30 (see FIG. 1)) tobe transmitted through and out of the tip receptor mount 32 via thecable 150.

The overmolded body 140 of the tip receptor mount 32 can include variousfeatures to assist in handling the tip receptor mount 32 and securingthe tip receptor mount 32 in place relative to a blade. For example, inthe embodiment illustrated in FIGS. 11A through 13, the neck portion 144includes a series of partial circumferential ridges 154 that can providea relatively secure grasping surface for an operator to manipulate thebody 140, and can also help to engage the neck portion 144 with bondingmaterial for anchoring the tip receptor mount 32 within a blade. In someembodiments, the ridge 154 can extend fully around the circumference ofthe neck portion 144, or can exhibit various other configurations, suchas a saw-toothed profile extending generally circumferentially aroundthe neck portion 144, or a straight (or other) profile extendinggenerally axially along the neck portion 144.

Generally, the tip receptor mount 32 can also include bonding wings withnon-conductive lattices, to help to secure the tip receptor mount 32within a blade. As illustrated in FIGS. 12A through 14, for example, apair of non-conductive, latticed bonding wings 156 flare generallyoutward from the connection portion 142 of the tip receptor mount, froma perspective moving from the lugs 148 towards the cable 150 (i.e., fromright to left in FIG. 11B). In the embodiment illustrated, the bondingwings 156 have a generally triangular perimeter, with generallytriangular or trapezoidal lattice openings 156 a separated by latticeribs 156 b. In other embodiments, other configurations are possible.When epoxy bonding paste, resin, or other similar bonding material isused to secure the tip receptor mount 32 within a blade, the bondingmaterial can fill the lattice openings 156 a in the bonding wings 156before curing, and thereby help to mechanically lock the tip receptormount 32 to the relevant blade structure. This can be useful, forexample, in helping to prevent solid metal tips (e.g., the tip receptor30) from being thrown from rotating blades in cases where a downconductor fractures near the tip of a blade.

As illustrated in FIGS. 15A and 15B, the tip receptor 30 can includevarious mounting features corresponding to the lugs 148 (or otherattachment mechanisms) of the tip receptor mount 32. In the embodimentillustrated, the tip receptor 30 includes a set of three rectangularapertures 160 with rounded blind ends corresponding to the geometry ofthe three lugs 148 of the tip receptor mount 32. The tip receptor 30further includes three blind, tapped apertures 162 extendingperpendicularly through the tip receptor 30 to intersect the rectangularapertures 160. In the embodiment illustrated, two of the apertures 162extend from the one side of the tip receptor 30 and one of the apertures162 extends from the opposite side of the tip receptor 30. In otherembodiments, other configurations are possible, including configurationswith different numbers of apertures.

During installation as part of the LP system 20, the tip receptor mount32 can be secured to the tip receptor 30 using the lugs 148. Forexample, as illustrated in FIGS. 16A and 16B, the three lugs 148 on theillustrated tip receptor mount 32 can be inserted into the rectangularapertures 160 and secured therein using bolts 158 that extend throughthe tapped apertures 162 to engage the lugs 148. Accordingly, electricalcurrent entering the tip receptor 30 (e.g., due to a lightning strike)can travel into the tip receptor mount 32 via the lugs 148, beforepassing into the cable 150 and onward to ground.

In the embodiment illustrated in FIGS. 16A and 16B, three of the bolts158 are used to secure the tip receptor 30 to the three lugs 148, with acentral one of the bolts 158 extending into a central one of the lugs148 (and the tip receptor 30) in an opposite direction than the two sidebolts 158 (only one of the bolts 158 is illustrated in FIG. 16B). Inother embodiments, other configurations are possible. In someembodiments, for example, different numbers, shapes, or arrangements oflugs and corresponding apertures can be used. In some embodiment, thelugs can include tapped holes, to receive bolts extending throughcorresponding apertures in the tip receptor.

Usefully, due to the configurable nature embodied in the tip receptormount 32 and the tip receptor 30, a particular tip receptor (andcorresponding tip receptor mount) according to the invention can becustomized to accommodate a particular blade or blade tip design, asneeded. As illustrated in FIG. 17, for example, a tip receptor mount 32a can be configured with a generally similarly exterior profile as thetip receptor mount 32 illustrated in FIGS. 12A through 14. In contrastto the tip receptor mount 32, however, the tip receptor mount 32 aincludes only two lugs 148 a, as may correspond to a tip receptor (notshown) with only two mounting locations (e.g., a smaller, thinner, orotherwise differently shaped tip receptor as compared to the tipreceptor 30 of FIGS. 15A and 15B). Similarly, in other embodiments (notshown), the size or orientation of the bolt holes in lugs of a tipreceptor mount can be varied, as can aspects of various other features.

As noted above, embodiments of the disclosed LP system (e.g., the LPsystem 20 of FIG. 1) can be installed relatively efficiently in a blade,as compared to conventional systems and conventional installationprocesses. Generally, in this regard, various sockets can be molded intotwo separate blade walls, then removable tabs removed from the bottomwalls of the sockets in order to provide generally uniform holes throughthe blade walls (via the sockets). A first set of receptor plugs canthen be secured to the sockets on a first of the blade walls, and asecond set of receptor plugs can be temporarily secured to the firstblade wall. The blade walls can be joined together, so that the receptorplugs (including those secured to sockets and those temporarily securedto the blade wall) are disposed within the interior of the blade. A toolcan then be extended through the hole in each of the sockets on thesecond blade wall to engage a corresponding one of the temporarilysecured receptor plugs and move that receptor plug into engagement withthe relevant socket. Finally, receptor elements (e.g., receptor disks)can be secured to the various receptor plugs via the openings in thesockets.

As one example, FIGS. 18A through 18K illustrate a process forinstalling two of the sockets 34 into a blade 170 (see FIGS. 18J and18K), along with a corresponding two of the side receptor plugs 36 andthe side receptor disks 38.

As illustrated in FIG. 18A, one of the sockets 34 can first be placed ona blade mold 172, with the bottom plate 122 (and the tear-away tab 124)seated against the blade mold 172. As illustrated in FIG. 18B, a lowerblade wall 174 can then be built and resin pulled therethrough,according to appropriate methods of blade manufacturing. When the resinhas cured and the blade mold 172 has been removed, the socket 34 willaccordingly be molded into the blade wall 174, with the bottom plate 122(and the tear-away tab 124) at an exterior surface of the blade wall174, and with the cylindrical and annular recesses 112 and 114 of thesocket 34 opening at an interior surface of the blade wall 174.

As the resin is pulled and cured, the configuration of the socket 34 canprovide various benefits. As one example, the perimeter flange 102 ofthe socket can provide a defined mounting surface for materials (e.g.,tacky tape) that can be used to prevent resin from flowing into unwantedlocations. Likewise, the bottom plate 122, with the tear-away tab 124intact, can prevents resin from entering into the interior of the socket34 from the bottom of the socket 34 during the resin dispersal process.

As another benefit, the configuration of the perimeter flange 102 canhelp to anchor the socket 34 in place relative to the blade wall 174.For example, as resin is pulled, the resin can flow over the angled lip104 on the perimeter flange 102 (see, e.g., FIG. 18B), which can help tolock the socket 34 into the blade wall 174 and thereby help to preventthe socket 34 from moving towards the interior blade cavity (i.e.,upward from the perspective of FIG. 18B) once the resin has cured.Likewise, because the radial extent of the perimeter flange 102 isgenerally larger than that of the cylindrical body 100 of the socket 34,the flange can generally help to prevent the socket 34 from movingtowards the exterior of the blade (i.e., downwards from the perspectiveof FIG. 18B).

In some embodiments, the angled lip 104 can be configured differently,while still helping to anchor the socket 34 in place relative to theblade wall 174. For example, in some embodiments, the angled lip 104 canbe configured as a stepped (e.g., right-angle) feature. Similarly, insome embodiments, the angled lip 104 can include holes (e.g., circularholes) to receive resin as the blade wall 174 is formed.

As still another benefit, once encapsulated by resin during thedispersal process, the gussets 108 around the exterior of thecylindrical body 100 can provide an anti-rotational lock relative to theblade wall 174. Further, because the bottom plate 122 can be seateddirectly on the blade mold 172, the socket 34 can be automaticallyaligned to support one of the receptor disks 38 (see, e.g., FIG. 18J)with the receptor disk 38 at an appropriate depth and angular alignmentrelative to the exterior surface of the blade wall 174.

In some embodiments, the sockets 34 can be configured in other ways toresist rotation once the socket 34 is molded into the blade wall 174.For example, one or more of the sockets 34 can include saw-tooth orother external patterns or contours on the relevant cylindrical body 100(or elsewhere) to provide an anti-rotational lock relative to the bladewall 174.

In the embodiment illustrated in FIGS. 18A-18H, the resin layer of bladewall 174 is formed directly on the blade mold 172 as the resin ispulled. In other embodiments, various layers of material can beinterposed between the blade mold 172 and the resin layer of the bladewall 174. In some embodiments, accordingly, the socket 34 can be seateddirectly on the blade mold 172 (e.g., in a cut-out in one or morerelevant layers). In some embodiment, the socket 34 can be seatedindirectly on the mold, and can be seated directly on one or more layersabove the mold 172. It will be understood that, in either of theseconfigurations, the socket 34 can be viewed as having been placed (orseated) “on” the blade mold 172 for the formation process.

As illustrated in FIGS. 18B and 18C, after the blade wall 174 has cured,the tear-away tab 124 of the socket 34 can be removed (e.g., using thegripping feature 126 (see FIG. 18B)), so that the circular hole 130 inthe socket 34 provides a consistent, engineered opening in the bladewall 174. In this regard, despite the removal of the tear-away tab 124,the welded seams of the bottom plate 122 can help to keep water anddebris from entering the interior of the blade 170 through the socket34.

As illustrated in FIG. 18D, once the socket 34 is appropriately seatedin the blade wall 174, one of the side receptor plugs 36 can be securedto the socket 34. In the embodiment illustrated, for example, the sidereceptor plug 36 can be positioned with the shell portion 62 and theopen end 66 generally aligned with the central opening 106 and thecircular hole 130 of the socket 34. Generally axial force can then beapplied to snap the retention shoulders 72 (see, e.g., FIG. 4A) past theretention shoulders 118 (see, e.g., FIG. 6C) and thereby to secure theside receptor plug 36 to the socket 34 with a snap fit connection. Inthis configuration, the teeth 74 on the side receptor plug 36 (see,e.g., FIG. 4A) can also engage the teeth 120 on the socket 34 (see,e.g., FIG. 6C) in order to provide anti-rotation force to the sidereceptor plug 36 (relative to the socket 34). With the side receptorplug 36 thus installed, the shoulder 58 of the side receptor plug 36 canseat against (e.g., directly, or via a gasket or other element) thecylindrical flange 116 of the socket 34 to appropriately locate theretention shoulders 72 and the teeth 74 relative to the retentionshoulders 118 and the teeth 120.

Due to the circumferential arrangement of the respective sets of theretention shoulders 72 and 118 and the teeth 74 and 120, the socket 34and side receptor plug 36 can generally be secured to one anotherregardless of the particular relative rotational orientations of thesocket 34 and the side receptor plug 36. This can be useful, forexample, in order to allow the cable 84 (see, e.g., FIG. 18D) to extendaway from the socket 34 at any number of angles, as appropriate for theparticular design of the relevant LP system.

With the side receptor plug 36 secured to the socket 34, as illustratedin FIG. 18D, the side receptor plug 36 can generally close the socket 34to infiltration of water and debris into the interior of the blade 170.In some embodiments, one or more sealing elements such as gaskets,over-molding, silicon, adhesive, and so on (not shown) can be disposedbetween the side receptor plug 36 and the socket 34 (e.g., at thecylindrical flange 116 (see, e.g., FIG. 6C)), or at other locations, inorder to further seal the assembly.

As illustrated in FIGS. 18E and 18F, before the blade 170 is fullyclosed, additional side receptor plugs can be secured to the interiorsurface of the blade wall 174. For example, a clip 176 (see FIG. 18E)can be secured to the interior surface of the blade wall 174, and then acable for another one of the side receptor plugs 36 can be secured tothe clip 176 (see FIG. 18F) with the open end 66 of the side receptorplug 36 facing away from the blade wall 174. In other embodiments, aside receptor plug (or other component) can be secured to the blade wall174 in other ways (e.g., with adhesives).

With an appropriate number of the side receptor plugs 36 secured incorresponding sockets 34 in the blade wall 174, and with an appropriatenumber of the side receptor plugs 36 clipped (or otherwise adhered) tothe interior surface of the blade wall 174, an upper blade wall 178 canbe installed, thereby fully defining the blade 170 and the correspondinginterior blade cavity 180 (see FIG. 18G). As illustrated in FIG. 18G,one (or more) of the sockets 34 can be molded into the blade wall 178before the blade wall 178 is installed, with the location of thesocket(s) 34 in the blade wall 178 generally corresponding to thelocation of the side receptor plug(s) 36 that have been clipped (orotherwise adhered) to the interior surface of the blade wall 174.

Once the blade walls 174 and 178 have been joined, a tool can beinserted into the sockets 34 in the blade wall 178, engaged with thecorresponding side receptor plugs 36 that were clipped (or otherwisetemporarily attached) to the blade wall 174, then used to lift the sidereceptor plug 36 into engagement with the socket 34. As illustrated inFIGS. 18H and 18I, for example, a rod 182 with a threaded engagement nut184 can be inserted into the socket 34, threaded onto the bolt 76 of theside receptor plug 36 (see FIG. 18G), used to pull the receptor plug 36into engagement with the relevant socket 34, and then unscrewed from thebolt 76. In this way, for example, the side receptor plugs 36 (and sidereceptors generally) can be installed on the upper and lower walls 178and 174 of the blade 170 without the need to cut and repair holes in theblade 170.

As illustrated in FIG. 18J, once the side receptor plugs 36 have beensecured to the respective sockets 34, respective side receptor disks 38(or other receptor elements) can be secured to the side receptor plugs36. As also noted above, the installation of the sockets 34 directlyinto the blade walls 174 and 178 during the manufacture of the blade170, and the relative geometry of the sockets 34 and the side receptorplugs 36, can help to support the side receptor disks 38 with therespective receptor surfaces 38 a in appropriately flush alignment withthe exterior surfaces of the blade walls 174 and 178.

During installation and thereafter, the flanges 116 in the side receptorplugs 36 can interact with the shoulders 136 on the receptor disks 38 tohelp to prevent the receptor disks 38 from passing into the interior ofthe blade 170 (e.g., if one of the side receptor plugs 36 isinadvertently removed from its respective socket 34). Further, in theevent that one of the side receptor plugs 36 was not properly seated onthe respective socket 34 when initially installed, the relevant flange116 can bear on the relevant shoulder 136 as the side receptor disk 38is tightened onto the relevant bolt 76, to pull the side receptor plug36 into an appropriate engagement with the socket 34.

As noted above, the inter-engagement of the teeth 74 and 120 on the sidereceptor plugs 36 and the sockets 34 can provide anti-rotational force,as well as allowing for different relative angular alignment ofrespective pairs of the side receptor plugs 36 and the sockets 34. Insome embodiments, the teeth 74 and 120 can be configured to providesufficient anti-rotational force so as to allow a predetermined level oftorque to be applied to secure the receptor disks 38 to the respectiveside receptor plugs 36.

It will be understood that the particular sequence of steps discussedabove with regard to FIGS. 18A through 18J are presented as an exampleonly. In other embodiments, other methods of installation are possible.For example, in some implementations, the side receptor disk 38 can beinstalled before the blade 170 is closed, or at other times during theinstallation process. Similarly, in some implementations, the tear-awaytab 124 can be removed at a different time than is expressly illustratedand discussed above.

It will further be understood that the general method of installationdiscussed above can be applied to an LP system with a differentarrangement than that illustrated in FIGS. 18A through 18J. For example,the discussed method can be used with LP systems that include differentnumbers, configurations, and arrangements of side receptor plugs,sockets, and side receptor disks, or other components than thoseexpressly illustrated and discussed above.

Thus, embodiments of the disclosed LP system and method of installationcan provide various benefits compared to conventional LP systems andmethods of installation. For example, in some embodiments, the disclosedLP system can allow for highly customizable configuration of tip andside receptors for wind turbine blades, and can allow side receptordisks to be accurately installed on both sides of a blade withoutrequiring the blades to be cut and then repaired.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the invention.Various modifications to these embodiments will be readily apparent tothose skilled in the art, and the generic principles defined herein maybe applied to other embodiments without departing from the spirit orscope of the invention. Thus, the invention is not intended to belimited to the embodiments shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

The invention claimed is:
 1. A method of installing a lightning protection system in a blade wall formed on a mold, the lightning protection system including a receptor plug, a receptor element, and a socket with a bottom wall, the method comprising: placing the bottom wall of the socket on the mold; forming the blade wall on the mold so that the blade wall is formed around, and at least partly includes, the socket; removing at least part of the bottom wall of the socket to provide an opening through the blade wall via the socket; securing the receptor plug to the socket, with the receptor plug on an interior side of the blade wall; and after removing the at least part of the bottom wall, securing the receptor element to the receptor plug via the opening.
 2. The method of claim 1, wherein removing the at least part of the bottom wall of the socket includes manually removing a tear-away tab from the socket to provide the opening through the blade wall via the socket.
 3. The method of claim 1, wherein securing the receptor plug to the socket includes engaging a plurality of first teeth on the receptor plug with a plurality of second teeth on the socket to resist rotation of the receptor plug relative to the socket.
 4. The method of claim 3, wherein securing the receptor plug to the socket further includes engaging a first retention shoulder of the receptor plug with a second retention shoulder of the socket.
 5. The method of claim 4, wherein the receptor plug includes a retention tab that includes the first retention shoulder and the plurality of first teeth; and wherein engaging the first retention shoulder with the second retention shoulder includes inserting the retention tab into a central opening of the socket to cause the first retention shoulder to engage the second retention shoulder and to cause the plurality of first teeth to engage the plurality of second teeth.
 6. The method of claim 1, wherein the blade wall is a first blade wall, the method further comprising: before securing the receptor plug to the socket: forming a second blade wall; temporarily securing the receptor plug to an interior side of the second blade wall; and joining the first blade wall to the second blade wall to define a blade cavity, with the receptor plug disposed within the blade cavity; wherein securing the receptor plug to the socket includes: after removing the at least part of the bottom wall of the socket, accessing the receptor plug via the opening to remove the receptor plug from the second blade wall and secure the receptor plug to the socket.
 7. The method of claim 6, wherein securing the receptor plug to the socket further includes: pulling the receptor plug, with a tool inserted through the opening, to form a snap fit connection between the receptor plug and the socket, with a plurality of first teeth on the receptor plug engaging a plurality of second teeth on the socket to resist rotation of the receptor plug relative to the socket.
 8. A method of installing a lightning protection system in a wind turbine blade with a first blade wall formed on a first blade mold, a second blade wall formed on a second blade mold, and a blade cavity formed when the first blade wall is secured to the second blade wall, the lightning protection system including a first socket with a first bottom wall, a second socket with a second bottom wall, a first receptor plug, a second receptor plug, a first receptor element, and a second receptor element, the method comprising: placing the first bottom wall of the first socket on the first blade mold; forming the first blade wall on the first blade mold so that the first blade wall is formed around, and at least partly includes, the first socket; after forming the first blade wall, providing a first opening through the first blade wall via the first bottom wall of the first socket; securing the first receptor plug to the first socket with the first receptor plug at least partly disposed on an interior side of the first blade wall; placing the second bottom wall of the second socket on the second blade mold; forming the second blade wall on the second blade mold so that the second blade wall is formed around, and at least partly includes, the second socket; joining the first blade wall to the second blade wall to form the blade cavity, with the second receptor plug disposed within the blade cavity; after forming the second blade wall, providing a second opening through the second blade wall via the second bottom wall of the second socket; and accessing the second receptor plug via the second opening to secure the second receptor plug to the second socket.
 9. The method of claim 8, wherein providing one or more of the first or second openings includes one or more of: removing a part of the first bottom wall of the first socket after the first blade wall is formed; or removing a part of the second bottom wall of the second socket after the second blade wall is formed.
 10. The method of claim 8, with the first socket including an internal flange and the first receptor element includes a first shoulder, the method further comprising: as part of securing the first receptor element to the first receptor plug, seating the first shoulder of the first receptor element against the internal flange of the first socket to urge the first receptor plug towards the first socket.
 11. The method of claim 8, with the first socket including an exterior flange with an angled lip, the method further comprising: as part of forming the first blade wall on the first blade mold, forming the first blade wall with the angled lip at least partly disposed within the first blade wall.
 12. The method of claim 8, wherein, when the first receptor element is secured to the first receptor plug, an exterior surface of the first receptor element is disposed substantially in parallel with an exterior surface of the first blade wall.
 13. The method of claim 8, further comprising, before joining the first blade wall to the second blade wall to form the blade cavity, temporarily securing the second receptor plug to the interior side of the first blade wall; and wherein accessing the second receptor plug via the second opening to secure the second receptor plug to the second socket includes engaging the second receptor plug, via the second opening, to remove the second receptor plug from the first blade wall.
 14. The method of claim 8, further comprising: after securing the first and second receptor plugs to the first and second sockets, respectively, securing the first receptor element to the first receptor plug via the first opening and securing the second receptor element to the second receptor plug via the second opening.
 15. A method of installing a lightning protection system in a wind turbine blade, the method comprising: forming a first blade wall around a first socket, so that an integrally formed first socket wall of the first socket separates a first internal opening of the first socket from an exterior side of the first blade wall; after forming the first blade wall, removing at least part of the integrally formed first socket wall to provide a first opening through the first blade wall into the first internal opening of the first socket; securing a first receptor plug to the first socket with the first receptor plug at least partly disposed to an interior side of the first blade wall; and securing a first receptor element to the lightning protection system to provide a conductive path from the exterior side of the first blade wall to the first receptor plug via the first internal opening of the first socket.
 16. The method of claim 15, wherein securing the first receptor plug to the first socket includes engaging a plurality of first plug teeth on the first receptor plug with a plurality of first socket teeth on the first socket to resist rotation of the first receptor plug relative to the first socket.
 17. The method of claim 16, wherein securing the first receptor element to the lightning protection system includes securing the first receptor element in threaded engagement with the first receptor plug.
 18. The method of claim 15, further comprising: forming a second blade wall around a second socket, so that a second socket wall of the second socket separates a second internal opening of the second socket from an exterior side of the second blade wall; removing at least part of the second socket wall to provide a second opening through the second blade wall into the second internal opening of the second socket; securing the first blade wall and the second blade wall to form a blade cavity, with a second receptor plug within the blade cavity; extending a tool through the second internal opening of the second socket to move the second receptor plug to be secured to the second socket; and securing a second receptor element to the lightning protection system to provide a conductive path from the exterior side of the second blade wall to the second receptor plug via the second internal opening of the second socket.
 19. The method of claim 18, wherein securing the second receptor plug to the second socket includes causing a snap-fit engagement of the second receptor plug and the second socket; and wherein securing the second receptor element to the lightning protection system includes securing the second receptor element in threaded engagement with the second receptor plug.
 20. The method of claim 15, with the first socket being an integrally formed body, wherein removing the at least part of the first socket wall includes removing part of the integrally formed body. 